i Register
In some senses, ranter is marked as obsolete, derogatory, historical. Watch for register when choosing this word.
noun
One who rants; a noisy, boisterous speaker or declaimer.
A jovial fellow.
noun
A member of an alleged sect in the time of the English Commonwealth (1649–1660) who were regarded as heretical by the established church.
One of the Primitive Methodists, who seceded from the Wesleyan Methodists on the ground of their deficiency in fervour and zeal.